Growing Trilliums Indoors

(Question)

I wish to try and grow Trilliums indoors in containers and want to get advice on the best way to do this. I have some growing in my backyard under a red maple tree in a very dark, fairly wet, and relatively cool spot – they have thrived there for many years but die everywhere else in my yard.

I have just bought two Trillium erectum and two Trilium gladiflorum – I plan on putting one of each under that maple tree but with the other of each I want to try the indoor container. I realize this is unconventional but it is an experiment – I expect it to fail but want to learn as much as possible in the exercise. Given that a few questions:

– what size of container should I try?
– what type of potting soil?
– how should I decide when to water?
– should I grow under lights? if so how intense and how long a daily exposure?
– any other thoughts?

Thanks very much

(Answer)

There doesn’t appear to have been much research conducted into the possibility of growing Trilliums – or indeed any other woodland plants / spring ephemerals – indoors in containers. The Trillium is an herbaceous perennial with a long period of dormancy (from summer through to the following spring). Once its leaves have died back it uses the protection of the soil in its woodland setting to regenerate from the roots. This may be particularly difficult if not impossible to achieve in an indoor setting. The Trilliums that are thriving in your back garden are obviously in the right place.

Because Trilliums do not transplant well, my instinct would be not to disturb the pot or the soil that your Trillium has been planted in, perhaps only top-dressing it with a leaf mulch to emulate as much as possible its moisture-retaining natural setting. Trilliums need regular watering; early dormancy can occur if they are allowed to dry out. Trilliums prefer part- to full-shade, so artificial lights would not be recommended.

While it may be possible to keep your Trilliums alive indoors in containers through the summer, assuming you are able to replicate their deep woodland setting, they are highly unlikely to overwinter successfully indoors. You may have more success in overwintering them if you place the pot into your garden soil in a moist and shady spot through the fall and winter so that the required period of dormancy in cold temperatures can take place.

It is always fun to experiment, but because Trilliums require such specific growing conditions, it is doubtful that your experiment will be successful. Our recommendation would be to plant all your new Trilliums outdoors in your garden where you know they will thrive in their preferred habitat, and where you can enjoy their ephemeral spring beauty for years to come.